Localised structures have taken an important place within the study of reaction-transport systems as they are ubiquitous within the theory of such systems and different applications. If we study these structures critically, we must start with the premise that nature dislikes wasting energy. In that context, nature and systems try to minimise the energy they need. My talk will delve into amplitude equations and the formulation of energy functionals that allow us to study Maxwell points, which are the points at which two solutions have the same minimal energy and the system oscillates around them. Furthermore, I will give the main ideas for this in the stationary case close to a codimension-2 Turing bifurcation point and spatiotemporal codimension-2 Turing-wave bifurcations.